Abstract
The aim of this study was to evaluate the antimicrobial resistance patterns of Pseudomonas aeruginosa isolates from hospital wastewater treatment system (HWTS) and clinical specimens in a hospital of Rio de Janeiro city, Brazil. Forty-three isolates obtained from four of the five steps of the HWTS (n = 27) and clinical samples (n = 16) from patients were analyzed regarding their susceptibility profiles to 12 antibiotics. Clinical isolates exhibited higher resistance profiles to antibiotics than wastewater isolates. However, out of 27 isolates from sewage, 62.9% showed decreased susceptibility to aztreonam while 50% of clinical isolates were resistant to this antibiotic. Isolates were not detected at the chlorination stage but they were obtained from the following stage of the treatment revealing the capacity of regrowth after chlorinated sewage effluent. To our knowledge, this is the first study reporting decreased aztreonam susceptibility among P. aeruginosa isolates from a hospital wastewater treatment system. Further investigations are being conducted by our laboratory including a larger sampling program in order to obtain more data.
Acknowledgments
We gratefully acknowledge the Subsecretaria de Gestão das Bacias Hidrográficas, Rio-Águas, Prefeitura do Rio de Janeiro, and the hospital who kindly authorized the collection of the wastewater and clinical samples. We also would like to thank Dr Ivano de Filippis for his critical reading of the manuscript. This work was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and INCQS/FIOCRUZ.